I’ve encountered upselling a couple of times, saw an EE girl in Milton Keynes years ago, arranged a 3 hour booking and when I got there she asked me if I wanted her friend to join in for double the money, I said I couldn’t afford it and she then said same price but half the time for 2 girls, only decent 3some I’ve ever had, 2 fantastic girls, I was drained after 90 mins with those 2.
Only time I’ve ever experienced a WG to do herself out of money, can only think they were friends and shared their earnings.